Rolling mills



J. D. NORTH ROLLING MILLS May 16, 1961 nited States Patent C)v ROLLING MILLS John D. North, Bridgnorth, England, assignor to Boulton au Arcraft Limited, Codsall, near Wolverhampton,

ng an Filed May 11, 1959, Ser. No. 812,202

Claims priority, application Great Britain May 14, 1958 13 Claims. (Cl. 242-7553) This invention relates to rolling, for example for rolling sheet metal, and aims at providing means for maintaining a constant tension in the sheet wound on the take-up roll.

According to the invention the axis of the take-up roll is free to move under the action of the tension in the sheet being rolled against the vaction of a low rate spring. Movement of the roll from a predetermined position is detected by means for applying a signal to a servo system which control a motor driving the take-up roll and the speed of the motor is controlled so as to maintain the de sired tension, the motor speed being varied until the takeup roll returns to its predetermined position.

Because the diameter of the take-up roll increases as the strip is wound on to it the direction of tension in the strip will vary from what it was initially unless the axis of the roll is allowed to move in a direction at right angles to the initial direction of tension with the result that there will be a small error between the tension as measured by the spring and that in the strip. To avoid this error the take-up roll is preferably mounted so as to be movable in a direction at 45 to the initial direction of tension against the action of a' IloW rate spring. That is to say, it is mounted so as to have a component of its movement in the initial direction of tension and at iight'angles to it.

In this preferred construction a displacement pick-Cif device is mounted adjacent the roll in a plane parallel to the direct-ion of initial tension and passing through the 4axis of the roll. If due to a change in the rolling speed, or

a progressive increase in diameter of the take-up roll, the linear rate of winding is not equal to the rate of rolling, then the axis of the roll will tend to move along a path at 45 to the initial tension direction. The movement of the axis will be sensed by the pick-01T device which relays a signal to a servo system controlling the speed of the take-up roll motor. The motor speed is so controlled as Vto make the tension in the strip what it was initially and the take-up'roll is pulled back to a position whereon a tangent to the outside of the roll at iight angles to the .initial direction of tension and passing through the sensing point is returned to its initial position.

The low rate spring against which the strip tension acts can be, and preferably is, of a fluid type.

So that the invention will be clearly understood a rolling mill installation wherein the direction of rolling is horizontal and embodying the invention will now be described with reference to the accompanying drawing.

The drawing shows diagrammatically a strip being passed through the nip of a pair of rolls of a rolling mill 2 low rate uid type spring 7. Spring 7 is charged from an accumulator 8 itself charged by pump 9.

A tension pick-off device 10 is mounted adjacent the takemp roll with a sensing finger 11 touching the roll and arranged to be movable in a horizontal plane passing through the axis of the roll. 'Ihe sensing linger 11 is maintained in the plane passing through the roll axis by being mounted so as to be slid vertically in a bracket 12 on the ramp by an arm 13 projecting from the carriage. Movement of the roll relatively to the finger 11 causes the pick-off device 10 to emit a signal which is relayed to an amplifier 14 controlling the torque motor 15 of a control valve 16. This valve controls the output of a variable delivery pump 17 which supplies the iiuid to operate the hydraulic motor 4.

Now if there is a change in the rolling speed and the linear rate of winding is not equal to the rate of rolling the carriage 5 will move in its track thereby causing the finger 11 to be displaced which emits a signal causing the speed of the motor to be varied so as to restore the strip tension to what it was originally. Likewise when there is an increase in roll diameter the linear rate of winding will again depart from the rate of 'rolling and the carriage will move up or down its ramp thereby again causing a signal to be emitted which leads to a change in the motor speed. |In either case the change in speed Will cause the roll to be returned to a position wherein a vertical tangent 18 to the roll passing through the sensing point will be in the same plane as it was originally.

I claim:

l. A rolling mill installation including a motor driven take-up roll, bearings supporting the take-up roll, a straight track on which the bearings slide in a straight path under the tension applied by the sheet being wound on to the roll, a llow rate uid type spring resisting the movement of the take-up roll and a servo-system operated in response to the movement of the roll to vary the speed of the roll motor `so as to maintain a predetermined tension in the sheet.`

V2. A rolling mill installation including a motor driven take-up roll, bearings supporting the take-up roll, a straight track at 45 to the direction of the initial tension in the sheet being rolled on which the bearings slide in a straight path under the tension applied by the sheet being wound on to the roll, a loW rate iiuid type spring resisting the movement of the take-up roll and a servosystem operated in response to the movement of the -roll to vary the speed of the roll motor so as to maintain a predetermined tension in the sheet.

3. A rolling mill installation including a motor driven take-up roll, bearings supporting the take-up roll, a straight track on which the bearings slide in a straight path under the tension in the sheet being wound on to the roll, a low rate fluid type spring resisting movement of the take-up roll and a servo-system operated in response to the movement of the roll to vary the speed of the roll motor until the take-up roll has returned to a position wherein a tangent to the roll at right angles to the direction of the initial tension and at one or other of the ends of the diameter of the roll parallel to the plane of the initial direction of tension is returned to its initial position.

4. A rolling mill installation including a motor driven taken-up roll, bearings supporting the take-up roll, on a straight track at 45 to the direction of initial tension of the sheet being rolled and which are movable in a straight path thereon under the tension in the sheet being wound on to the roll, a low rate spring resisting the movement of the take-up roll and a servo-system operated in response to the movement of the roll to vary the speed of the roll motor until the take-up roll has returned to a position wherein a tangent to the roll at right-angles to the direc- B tion of the initial tension and at one or other of the ends of the diameter of the roll parallel to the plane of the initial direction of tension is returned to its initial position.

5. A rolling mill installation including amotor driven take-up roll, bearings supporting the take-up roll, a straight track at 45 to the direction of the initial tension in the sheet being rolled on which the bearings slide in a straight path under the tension applied by the sheet being wound on the roll, a low rate liuid type spring resisting the movement ofthe take-up roll and a servo-system operated in response to the movement of the roll to vary the speed of the roll motor so as to maintain a predetermined tension in the sheet.

6. A rolling mill installation including a motor driven take-up roll, bearings supporting the take-up roll, a straight track at 45 to the direction of initial tension of the sheet being rolled on which the bearings slide in a straight path under the tension in the sheet being wound on to the roll, a low rate uid type spring resisting the movement of the take-up roll and a servo-system operated in response to the movement of the roll to vary the speed of the roll motor until the take-up roll has returned to a position wherein a tangent to the roll at right-angles to the direction of the initial tension and `at one or other of the ends of the diameter of the roll parallel to the plane of the initial direction of tension is returned to its initial position.

7. A rolling mill installation including a take-up roll, a hydraulic motor driving the takeup roll, bearings supporting the take-up roll, a straight track on which the bearings slide in a straight path, a low rate huidtype spring resisting the movement of the take-up roll and a servo-system operated in response to the roll movement, which system includes a variable output pump controlled by means Asensitive to a signal derived from movement of the roll so as to vary the pump output thereby controlling the speed of the roll motor in order to maintain aA predetermined tension in the sheet.

8. A rolling mill installation including a take-up roll, a hydraulickmotor driving the take-up roll, bearings supporting the take-up roll, a straight track at 45 to the direction of the initial tension in the sheet being rolled on which the bearings slide in a straight path under the tension in the sheet being wound on to the roll, a low Arate fluid type spring resisting the movement of the take-up roll and a servo-system operated in response to the roll movement, which system includes a variable output pump controlled by means sensitive to a signal derived from movement of the roll so as to vary the pump output thereby controlling the speed of the roll motor in order to maintain a predetermined tension in the sheet.

9. A rolling mill installation including a take-up roll, a hydraulic motor driving the take-up roll, bearings supporting the take-up roll, a straight track at 45 to the direction of the initial ltension in the sheet being rolled on which the bearings slide in a straight path under the tension in the sheet being wound on to the roll, a low rate fluid type spring resisting the movement of the take-up roll and a servo-system operated in response to the roll movement, which system includes a variable output pump controlled by means sensitive to a signal derived from movement of the roll so as to vary the pump output thereby controlling the speed of the roll motor in order to maintain a predetermined tension in the sheet.

10. A rolling mill installation including a take-up roll, a hydraulic motor driving the take-up roll, bearings supporting the take-up Iroll, a straight track at 45 to the direction of initial tension of the sheet being rolled on which the bearings slide in a straight path under the tension in the sheet being wound on the roll, a low rate fluid type spring resisting the movement of the take-up roll and a servo-system operated in-response to the movement of the roll, which system includes a variable output pump controlled by means sensitive to a signal derived from the movement ofthe roll so as to vary the pump output thereby varying the speed of the roll motor until the roll has returned to a position wherein a tangent to the roll at right-angles to the direction of initial tension and at one or other of the ends of the diameter of the roll parallel to the plane of the initial direction of tension is returned to its initial position.

11. A rolling mill installation including a motor driven take-up roll, bearings supporting the take-up roll, a straight track on which the bearingsy slide in astraight path under the tension in the sheet being wound on to the roll, `a low rate uid type spring resisting movement of the take-up roll anda servo-system operated in response to the movement of the roll to vary the speed of the roll motor until the take-up roll has returned to a position wherein atangent to the ,roll at right angles to the direction of the initial tension and at onefor other of the ends of the diameter of the roll parallel to the plane of the initial direction of tension is returned to its initial position.

l2. A rolling mill installation including a take-up roll, a hydraulic motor driving the take-up roll, bearings supportingthe take-up roll, a straight track on which the bearings slide in a straight path under the tension in the sheet being wound on the roll, a low rate uid type spring resisting lthe movement of the take-up roll and a servosystem operated in response to the movement of the lroll, which system includes a variable output pump controlled by means sensitive to a signal derived fromthe movement of the roll so as to vary the pump output thereby varying the speed of the roll motor until the roll has returned to a position wherein a tangent to the roll at right angles to .the direction of initial tension and at one or other of the ends of the diameter of the roll parallel to the plane of the initial direction of tension is returned to its initial position.

13. A rolling mill installation including a take-up roll, a hydraulic motorV driving the take-up roll, bearings supporting the take-up roll, a straight track on which the bearings slide in a straight path under the tension in the sheet being wound on the roll, a low rate liuid type spring resisting the movement of the take-up roll and a servosystem operated in response to the movement of the roll, which system includes a variable output pump controlled by means .sensitive to av signal derived from the movement of the roll so as to vary the pump output thereby varying the speedof the roll motor until the roll has returned to a position wherein a tangent to the roll at right angles to the direction of initial tension and at one or other of the ends of the diameter of the roll parallel to the plane of the initial direction of tension is returned to its initial position.

References Cited in the tile of this patent UNITED STATES PATENTS 2,167,549 Hudson July 25, 1939 2,214,333 Walsh et al. Sept. 10, 1940 2,460,694 Haswell Feb. l, 1949 2,507,297 Bouget May 9, 1950 

